Adapting and responding to the present era’s rapid technological and educational change requires educators to possess new knowledge, skills, and dispositions. With dissatisfaction regarding traditional teacher professional development (PD) well documented, educators have increasingly used digital sites to cultivate and extend Professional Learning Networks (PLNs) in order to learn and improve their practice. While many educators claim to benefit from PLNs, much remains unknown about how teachers conceive of PLNs and what they learn from them. In this paper we report the findings of a qualitative study in which we investigated teachers’ understandings of PLNs through the analysis of survey data from 732 participants in Pre-Kindergarten to 12th grade settings. The majority of respondents described multifaceted networks that incorporated a variety of different technologies and people, and many PLNs were described in terms of a combination of both online and offline elements.